Open frame diesel generator set in a concrete room

Representative photo. Your order is made to your specification by a verified seller. Photo: “diesel generator~hydroelectric power plant” by hydropower plant spare parts, CC BY 2.0.

Diesel generator supplier in Bangladesh

Need a diesel generator supplier in Bangladesh that checks the rating first? Give us the load, the large motors and the running hours; verified sellers quote against them, and we check sizing, derating and papers before the set reaches your site.

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Delivered by Roptan

Prefer to deal with suppliers yourself? Post it on the requirement board

Buying diesel generators in Bangladesh

A diesel generator couples a compression-ignition engine to an alternator on one frame, with controls and a fuel tank. Factories, hospitals, offices and apartment owners look for a diesel generator supplier in Bangladesh to cover power cuts or daily running. Large sets here are usually imported complete; a few are assembled locally from imported parts.

Share the load list, site and running hours. Roptan asks verified sellers to quote the same rating class, enclosure and scope, so prices compare like for like, checks the set and its papers, and delivers it. Installation and commissioning are the seller's, and you sign off after a load test you can witness.

Kinds of diesel generator

Open frame sets

Engine, alternator and controls on a bare skid, for a dedicated plant room. It usually costs less than a canopy set, but the room must handle ventilation, noise and exhaust.

Silent canopy sets

The set in an enclosure lined with sound-absorbing material, for sites without a plant room. Ask whether its noise figure is sound power or sound pressure at a stated distance; they differ.

Containerised sets

A large set built into a shipping container with tank, controls and power distribution; a 2,000 kW set can fit a 40-foot one. Choose it for big loads with no building.

Standby sets, with or without an ATS

Emergency standby power under ISO 8528-1 is typically outage backup on a varying load, not daily running. It usually has auto-start and an ATS that breaks before making, so the set cannot back-feed the grid; without them, changeover is manual.

Prime or continuous rated sets

Prime power is typically the main supply on a varying load, with no yearly running limit; continuous power carries a steady load around the clock. Choose them for off-grid sites and daily outages.

How to brief a diesel generator supplier in Bangladesh

Rating and duty: State the kVA and the ISO 8528-1 class, emergency standby, prime or continuous, plus the hours the set will run each day, so the engine is chosen for the duty and not only the load.
Motors and how they start: List each large motor's kW and starter: direct on line, star-delta, soft starter or drive. Starting kVA and the voltage dip you accept often decide the set size.
Alternator: Ask for insulation class, temperature rise, IP rating (IEC 60034-5) and conformity to ISO 8528-3. Variable-speed drives can call for a larger alternator than the running load suggests.
Alarms and shutdowns: Name them: low oil pressure, high coolant temperature, overspeed, overcrank, emergency stop, low and high fuel level, and battery charger fault.
Area and night running: State the area type, residential, commercial, mixed, industrial or silent, and whether the set runs at night: noise limits go by area and tighten after 9 pm.
Room to add a set: If a second set may follow, ask for controls that synchronise, matching frequency, phase and voltage, so paralleled sets usually share load in proportion to rating.

Noise rules, standards and test papers for diesel sets

Noise Pollution (Control) Rules 2025: In force since 24 November 2025, replacing the 2006 Rules. Rule 10 makes generator users fit acoustic enclosures, vibration isolation and silencers; Schedule 1 area limits apply day and night, and a breach is punishable.
IEC 60947-6-1: The IEC standard for transfer switching equipment up to 1,000 V AC, automatic transfer switches and their controllers included. Ask for conformity and a rating matched to the set.
ISO 8528-12: Covers sets that supply safety services in hospitals, high-rise buildings and public gathering places; ask for it on top of ISO 8528-1 if yours does.
Electricity Rules 2022: Set up the electricity licensing board and licences for electrical contractors, supervisors and electricians under the Electricity Act 2018. Ask the seller whether a licence applies to wiring your set, and who holds it.

What moves the price of a diesel generator

Housing: an open set usually costs less than a canopy set; a container adds its own tank, controls and distribution gear.
Motor starting: large motors' starting kVA and the voltage dip you accept can push the set or alternator up a size.
Import costs: large sets are usually imported, so exchange rates, duty and taxes move quotes; ask how long one holds.
Acceptance test: a hired load bank adds a line that a test on building load does not, but it proves the rating at full load.

Lead times and delivery

Sellers advertise common open and canopy ratings as ready stock, so a standard set can usually reach site soon after ordering. Containerised, paralleled or uncommon sets are usually imported to order, and foreign exchange, customs and tax steps can delay them. The plinth, cables and exhaust must be ready first. Roptan confirms dates in the quote.

Roptan delivers the set to your site. Sellers in Dhaka often advertise installation, testing and commissioning in the price, but the quote should say so. At handover, ask for signed factory and site test reports, load readings at each step, as-built drawings, alarm set-points, manuals and a VAT invoice (Mushak 6.3).

What we check for this order

Derated outputWe check the quoted kVA against the maker's derating curve at the temperature your plant room reaches in summer, not the ISO 3046-1 reference figure.
Motor starting marginWe check the seller's sizing against your large motors' starting kVA and the voltage dip you accept.
Stepped load testWe check the stepped load test: typically 25, 50 and 75 percent for 30 minutes each, then full load for at least an hour.
Trips and transferWe check that each specified shutdown trips and that transfer tests start from the ATS test switch, not the generator panel.

Questions buyers ask

Can a diesel generator run 24 hours a day?

Yes, if it is rated for it. A standby rating is for outages, not daily running. For a steady round-the-clock load choose a continuous rating; for a varying one, prime. With two synchronised sets, one can usually be serviced while the other runs.

Is a bigger generator the safer choice?

Not if it then runs lightly loaded: a diesel set at light load can suffer wet stacking, as unburnt fuel passes into the exhaust, and needs load bank runs to clear it. Diesel plant usually runs near its optimum at about 65 to 70 percent load.

Can you source a reconditioned diesel generator?

Yes, with extra checks. A second-hand or reconditioned set imported into Bangladesh usually needs an inspection of its condition and remaining life before customs clearance. Ask for that certificate, the engine's running hours and a full load test, and check the current Import Policy Order first.

Which HS code covers a diesel generator?

HS heading 8502, by output: 8502.11 up to 75 kVA, 8502.12 above 75 up to 375 kVA, 8502.13 above 375 kVA. Bangladesh adds its own digits to these six. Check that the code on an imported set's bill of entry fits the kVA on its rating plate.

How soon will I hear back about generators?

Within 48 hours of a complete requirement, with a price and a delivery date. A requirement is complete when it has the rating, where it is needed and by when.

Who do I deal with?

With Roptan, when Roptan manages the order: we buy from the verified seller and deliver to you. With the supplier directly, when you post on the requirement board and choose a quote yourself.